Switching of spontaneous electric polarization in the DyMnO3 multiferroic

For the DyMnO3 multiferroic with a modulated magnetic structure, switching of its spontaneous electric polarization (P ‖ c axis) near the ferroelectric transition (T < TFE ∼ 20 K) is revealed by measuring the dielectric hysteresis loops. It is found that the coercive field strongly increases as the temperature decreases (up to 2.6 kV/mm at 17.6 K). The values obtained for the spontaneous polarization are found to agree well with the data obtained from pyroelectric measurements. In addition, anomalies are observed in the temperature dependences of the spontaneous polarization Pc, dielectric constant ɛc, and magnetic susceptibility xb at T ∼ 6 K; these anomalies are attributed to the antiferromagnetic ordering of the Dy3+ ions.